Release plate for a collapsible culvert form

ABSTRACT

The form is used in the construction of box culverts or in buildings having linearly aligned rooms to provide for a progressive forming of the room side walls and ceiling. A pair of frame units are connected together for relative expansible and contractible movement and for vertical movement. A metal form assembly for laying the ceiling is supported on each frame unit, a first one of which assemblies carries a release plate that extends between the two form assemblies with its upper surface in the plane of the top surfaces of the form assemblies and its free end in abutting engagement with the second one of the form assemblies when the frame units are in their expanded positions. Coacting wedge members on the frame units and/or on the form assemblies facilitate the movement of the release plate to a position overlying the second one of the form assemblies when the frame units are in their contracted positions.

United States Patent Jennings 1 1 Sept. 26, 1972 s41 RELEASE PLATE FOR A 3,570,802 3/1971 Miller ..249/179 COLLAPSIBLE CULVERT FORM 2,557,631 6/1951 Callan ..249/178 [72] Inventor: Ralph L. Jennings, Des Moines,

Iowa 50313 [73] Assignee: Economy Forms Corporation; Des

Moines, Iowa [22] Filed: Feb. 24, 1970 [21] Appl. No.: 13,678

[52] US. Cl. ..249/11, 249/27/249/181 [51] Int. Cl. ..B28b 7/30 [58] Field of Search.. .249/11, 27, 29, 180, 181, 18 2, 249/184 186,l78,195,157,173; 25/131.50,131.6, 131 SC, 131 SD, 130B, 128 K; 18/D1G. 5

[56] References Cited UNITED STATES PATENTS 2,708,782 5/1955 Jessen ..25/131.6 2,547,946 4/1951 Jessen ..25/131.6 3,274,306 9/1966 Kesting ..249/27 X 3,476,351 11/1969 Burdett ..249/181 X- 2,306,503 12/1942 Sarosdy ..249/11 X 3,376,012 4/1968 Grammer ..249/184 X 1,305,299 6/1919 Marqua ..249/29 1,911,163 5/1933 Prowant ..25/131.5 D 2,114,785 4/1938 Porter ..25/131.6 X 2,683,912 7/1954 Serrell ..249/173 X Primary Examiner-4. Spencer Overholser Assistant ExaminerB. D. Tobor Attorney-Rudolph L. Lowell [57] ABSTRACT The form is used in the construction of box culverts or in buildings having linearly aligned rooms to provide for a progressive forming of the room side walls and ceiling. A pair of frame units are connected together for relative expansible and contractible movement and for vertical movement. A metal form assembly for laying the ceiling is supported on each frame unit, a first one of which assemblies carries a release plate that extends between the -two form assemblies with its upper surface in the plane of the top surfaces of the form assemblies and its free end in abutting engagement with the second one of the form assemblies when the frame units are in their expanded positions. Coacting wedge members on the frame units and/or on the form assemblies facilitate the movement of the release plate to a position overlying the second one of the form assemblies when the frame units are in their contracted positions.

2 Claims, 6 Drawing Figures RELEASE PLATE-FOR A COLLAPSIBLE CULVERT FORM SUMMARY OF THE INVENTION The box culvert form structure is capable of being collapsed and stripped away from the formed walls and ceiling without the removal or handling of any component parts of the form. Stripping of the form structure takes place efficiently so that the time and effort required to move the form structure for reuse in the progressive construction of an elongated wall and ceiling structure is reduced to a minimum. Additionally the arrangement of the release plate of the form structure in a position between and in the plane of the upper surfaces of the ceiling form systems, when the form structure is in an expanded position, results in a smooth ceiling surface without any parting lines or like surface irregularities.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an end perspective view of the form structure shown in an expanded position for forming the walls and ceiling of a culvert or elongated room structure;

'FIG. 2 is an enlarged detail elevational view looking in the direction of line 2 2 in FIG. 1 showing the position of the release plate, when the form structure is in the expanded position therefor;

FIG. 3 is illustrated similarly to FIG. 2 and shows the position of the release plate when the form structure is in the collapsed or retracted position therefor;

FIG. 4 is an enlarged and foreshortened end elevational view of the form structure in FIG. I shown in assembly relation with adjacent similar form structures to form multiple or side-by-side room or culvert structures; and

FIGS. 5 and 6 are sectional detail views as seen on lines 5 5 and 6 6, respectively, in FIG. 4.

DETAIL DESCRIPTION OF THE INVENTION The box culvert form structure, indicated generally at in FIGS. 1 and 4, includes a pair of frame units 16 and 17 each of which has a vertical side section 18 and a horizontal header section 19. The free end portions 21 of the header sections 19 (FIGS. 4 and 5) are arranged in a side by side relation for relative longitudinal adjustable movement. In an adjusted position the header sections 19 are connected together by bolt assemblies 22 extended through aligned holes 20 formed in the sections 19. Thus, on relative longitudinal movement of the end portions 21, the frame units 16 and 17 are movable toward and away from each other to retracted and expanded positions, respectively, for a purpose to appear later. This movement is accomplished by a ratchet jack 23 extended between and connected to an angle iron bracket depended from each of the header end portions 21 (FIGS. 4 and 5). On movement of the header sections 19 to an adjusted position, such position is maintained by the bolt assemblies 22 and an adjustable telescopic brace unit 24 (FIGS. 1 and 4) that extends between and is attached to a horizontal support member 26 which projects inwardly from each of the vertical side sections 18.

A ground movement of the culvert form structure 15 is provided by roller units 29, which are mounted to the underside of certain of the support members 26. Corresponding to the support arms 26 are manually operated lift jacks 31 which function to lift the roller units 29 out of ground engagement. The form structure 15 is thus capable of being rigidly supported on the lift jacks alone at an elevation dependent on the ceiling height of the box structure to be formed. As thus far described, it is seen that the frame units 16 and 17 of the culvert form structure 15 are adjustably movable toward and away from each other in directions longitudinally of the header sections 19 to expanded and contracted positions therefor. Likewise, it is seen that the frame units 16 and 17 are vertically movable by the lift jacks 31.

Metal form systems 32 and 32a corresponding to the frame units 16 and 17, are supported on corresponding header sections l9'with their inner ends 33 and 33a, respectively, facing each other. Each form system 32 and 32a is comprised of a plurality of metal forms 34 of a well-known type, each of which has a base portion 36 (FIG. 4) provided with an upright peripheral rim 37 formed with rows of transversely spaced openings (not shown) for interconnecting purposes. For a more detailed description of the metal forms 34 and their interconnection, reference is made to US. Pat. No. 2,870,516.

The inner end 33 of the form system 32 is equipped with a release plate 39 that is illustrated (FIGS. 2 and 3) as an angle iron member having a vertical leg 41 secured to the form system 32 by bolt assemblies 42. The horizontal leg 43 of the release plate 39 projects laterally toward the inner end 33a of the form system 32a with its top surface in the plane of the upper surface of the form system 32.

Secured to the inner end 330 of the form assembly 32a by bolt assemblies 44 is a vertical abutment plate 46 that has a bevelled upper edge 47 terminating below the plane of the upper surface of the form assembly 32a. The bevelled edge 47 is engageable in mating abutting engagement with a bevel edge 48 formed on the inner or free edge of the horizontal leg 43 of the release plate 39. The bevelled edges 47 and 48 form a miter joint between the release plate 39 and the abutment plate 46 when the frame units 16 and 17 are in the expanded positions therefor shown in FIGS. 1 and 4. Thus, as clearly appears in FIG. 2, the upper surface of the horizontal leg 43 is coplanar with the top surfaces of the form systems 32 and 32a to form a continuous smooth surface for the ceiling wall 49 that is to be formed.

A form system 51 comprised of a series of upright interconnected panels or forms 50 is secured to the vertical sections 18 of each of the form units 16 and 17 by tie rod assemblies 55. It is to be understood that the number and relative size of the metal forms 34 that are interconnected to construct the form systems 32, 32a and 51 are dependent upon the dimensions of the box structure to be formed. Thus, the form systems 32 and 32a in the expanded positions of the frame units 16 and 17, and the horizontal leg 43 of the release plate 39, provides the full area for the ceiling wall 49 and a form system 51 the full area of a side wall 52. For this purpose, a form system 51 will have a vertical dimension equal to the distance between the ceiling wall 49 and a pre-formed footing 53 that is integrally constructed with the floor or ground surface 54 on which the roller units 29 and lift jacks 31 are supported.

in the event a series of elongated box or room units are to be constructed in a side-by-side relation, the form structures in adjacent box units will be used in a complementary manner as shown in FIG. 4,'wherein form systems 51 of laterally adjacent form structures 15 are arranged to opposite sides of a common side wall 52. Where a single elongated box unit is to be formed, a usual form assembly, indicated at 56 in FIG. 1, is arranged in operative association with each of the form systems 51 of the form structure 15.

In use the box culvert form structure 15, with the frame units 16 and 17 in their retracted positions and the roller units 29 engageable with the ground surface 54, is rolled intoposition between the floor base molds or footings 53.'The lift jacks 31 are manipulated to move the roller units 29 out of ground engagement (FIG. 6) and to elevate the form structure 15 to a position wherein the vertical sections 18 are raised to a predetermined height relative to the footings 53. The frameunits l6 and 17 are then moved and retained in the laterally expanded positions therefor by the ratchet jacks 23 and adjustable telescopic units 24, so that the release plate 39 and abutment plate 46 are in their relative positions of FIG. 2. With a form system 51 operatively associated with a corresponding form assembly 56 (FIG. 1) or with a next adjacent form system 51 (FIG. 4) concrete is poured to form the ceiling wall 49 and side walls 52.

After the concrete has set the box or culvert form structure 15 is stripped from the walls and ceiling by initially lowering the lift jacks 31 to provide for the ground support of the frame units 16 and 17 on the roller units 29. The ratchet jacks 23 are then retracted to in turn move the header sections 19 inwardly toward each other to their positions illustrated in FIG. 3. On initiation of this inward movement of the header sections 19 the bevelled edges 47 and 48 on the release plate 39 and abutment plate 46, respectively, coact to direct the horizontal leg 43 of the release plate 39 into a position overlying the upper surface of the form system 32a whereby to strip or release the form systems 32 and 32a from the ceiling wall 49.

This stripping action of the form systems 32 and 320 from the ceiling wall 49 takes place concurrently with a stripping or pulling of the form systems 51 on the vertical sections 18 away from the side walls 52. Due to the flush engagement of bevelled edges 47 and 48, when the upper surface of leg 43 of the release plate 39 is in a plane common to the top surfaces of the form systems 32 and 32a the ceiling wall 49 is smooth and free of any parting lines or like surface projections. On the release of the culvert structure 15 from the ceiling wall and side walls, the collapsed or retracted structure 15 drops downwardly to a supported position on the roller units 29, for rolling movement to a next position providing for the progressive construction of the elongated box culvert or room.

it is clear that the elevation of the release plate 39 to a position wherein the horizontal leg 43 is in an overlying position with the upper surface of the form assembly 32a, as shown in FIG. 3, is facilitated by the cooperative action of the bevelled edges 47 and 48 of the release plate 39 and abutment plate 46, respectively. This lifting action on the release plate 39 by the bevelled edges 47 and 48 is complemented by the provision of a wedge member 57 that is secured to the header section 19 of the frame unit 17 for a cooperative action with the lower or free edge 58 of the vertical leg 41 of the release plate 39. When the units 16 and 17 are in their expanded positions of FIG. 2, a bevelled edge 59 on the wedge member 57 forms a miter joint with a bevel formed on the lower edge 58 of the vertical leg 41.

Thus, when the frame units 16 and 17 are moved inwardly toward each other, the bevelled edges 58 and 59 are moved toward each other whereby the wedge member 57 lifts the release plate 39 concurrently with the lifting of such plate by the coaction of the bevelled edges 47 and 48. Excessive wear on the bevelled edges 47 and 48 is thus appreciably reduced along with providing for an efficient release of the form systems 32 and 32a from the ceiling wall 49.

Iclaim:

l. A box culvert form comprising a pair of frame units, each frame unit having a vertical side section and a horizontal header section, a pair of form systems corresponding respectively to and supported by said frame units, one form system having a first portion with a first flat forming surface, the other form system having a second portion with a second flat forming surface, said first and second flat forming surfaces having inner ends facing each other, connecting means adjustably connecting said frame units for movement of the inner ends of said flat forming surfaces toward and away from each other to positions corresponding to respective retracted and expanded positions of the form, said first and second flat forming surfaces being in a common plane when said form is in the expanded position, a release plate having a flat exterior surface, securing means for securing said plate adjacent the inner end of said first portion such that said flat exterior surface is continuous with and in the plane of said first forming surface, said flat exterior surface extending across a gap formed between the inner ends of said first and second forming surfaces to form a continuous plane with both of said forming surfaces when said form is in the expanded position, first inclined surface means on the end of said release plate facing toward the inner end of said second forming surface, second inclined surface means on the second portion adjacent the inner end of said second forming surface, said first and second inclined surface means being in abutting sliding contact with one another such that movement of said inner ends of said first and second forming surfaces toward one another forces said second portion and associated second forming surface out of the plane of the first forming surface, and guiding means including respective abutting sliding surfaces arranged between said release plate and the header section supporting said first portion for assisting in initially guiding the relative movement of said first and second forming surfaces out of their common plane when retraction of the form is initiated.

2. A box culvert according to claim I, wherein said release plate is constructed L-shaped with the apex of the L positioned immediately adjacent said first forming surface, and one leg extending downwardly from said apex, and wherein one of the respective abutting sliding surfaces of said guiding means is arranged at the lower end of the downwardly depending leg of the release plate. 

1. A box culvert form comprising a pair of frame units, each frame unit having a vertical side section and a horizontal header section, a pair of form systems corresponding respectively to and supported by said frame units, one form system having a first portion with a first flat forming surface, the other form system having a second portion with a second flat forming surface, said first and second flat forming surfaces having inner ends facing each other, connecting means adjustably connecting said frame units for movement of the inner ends of said flat forming surfaces toward and away from each other to positions corresponding to respective retracted and expanded positions of the form, said first and second flat forming surfaces being in a common plane when said form is in the expanded position, a release plate having a flat exterior surface, securing means for securing said plate adjacent the inner end of said first portion such that said flat exterior surface is continuous with and in the plane of said first forming surface, said flat exterior surface extending across a gap formed between the inner ends of said first and second forming surfaces to form a continuous plane with both of said forming surfaces when said form is in the expanded position, first inclined surface means on the end of said release plate facing toward the inner end of said second forming surface, second inclined surface means on the second portion adjacent the inner end of said second forming surface, said first and second inclined surface means being in abutting sliding contact with one another such that movement of said inner ends of said first and second forming surfaces toward one another forces said second portion and associated second forming surface out of the plane of the first forming surface, and guiding means including respective abutting sliding surfaces arranged between said release plate and the header section supporting said first portion for assisting in initially guiding the relative movement of said first and second forming surfaces out of their common plane when retraction of the form is initiated.
 2. A box culvert according to claim 1, wherein said release plate is constructed L-shaped with the apex of the L positioned immediately adjacent said first forming surface, and one leg extending downwardly from said apex, and wherein one of the respective abutting sliding surfaces of said guiding means is arranged at the lower end of the downwardly depending leg of the release plate. 